Comparison of two independent aromatic hydroxylation assays in combination with intracerebral microdialysis to determine hydroxyl free radicals
Comparison of two independent aromatic hydroxylation assays in combination with intracerebral microdialysis to determine hydroxyl free radicals
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DOI：
10.1016/s0165-0270(01)00370-3
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发表时间：
2001-07-15
影响因子：
3
通讯作者：
Ferger, B
中科院分区：
文献类型：
--
作者：
Themann, C;Teismann, P;Ferger, B
用苯丙氨酸和水杨酸测定法研究了羟基自由基的产生。体外实验：苯丙氨酸（100 μ mol/1）或水杨酸（100 μ mol/1）在体外产生羟基自由基的Fenton体系中培养，同时增加等摩尔过氧化氢和亚铁离子的浓度（1.25 ~ 40 μ mol/1）。Fenton试剂浓度与苯丙氨酸衍生产物（邻位、间位、对酪氨酸）或水杨酸衍生产物（2,3-和2,5-二羟基苯甲酸（DHBA））之间的线性关系表明，苯丙氨酸和水杨酸都能以可靠的方式捕获羟基自由基。活体实验：Wistar大鼠植入微透析探针，纹状体灌注5 mmol/l苯丙氨酸或5 mmol/l水杨酸。在灌注液中添加多巴胺能神经毒素6-羟多巴胺（100 μ mol/l，流速2 μ /min， 60 min），与对照动物相比，显著增加了正酪氨酸和间酪氨酸或2,3- dhba的浓度。在回到刺激前的条件后，所有的增加都是快速可逆的。结果表明，苯基丙氨酸或水杨酸的芳香族羟基化反应是研究体内外羟基自由基形成的有效方法。讨论了两种方法的优缺点。(C) 2001 Elsevier Science B.V.版权所有
The phenylalanine- and salicylate assay were compared to investigate the production of hydroxyl free radicals. In vitro experiment: Phenylalanine (100 mu mol/1) or salicylic acid (100 mu mol/1) were incubated in a hydroxyl radical generating in vitro Fenton system with increasing concentrations (1.25-40 mu mol/1) of equimolar hydrogen peroxide and ferrous ions. Both, phenylalanine and salicylic acid were able to trap hydroxyl radicals in a reliable way indicated by the linear relationship between the concentration of the Fenton reagents and either the phenylalanine derived products (ortho-, meta-, para-tyrosine) or the salicylic acid-derived products (2,3- and 2,5-dihydroxybenzoic acid (DHBA)). In vivo experiment: Wistar rats were implanted with microdialysis probes and striatal perfusion with either 5 mmol/l phenylalanine or 5 mmol/l salicylic acid was performed. Addition of the dopaminergic neurotoxin 6-hydroxydopamine (100 mu mol/l, flow rate 2 mul/min, 60 min) to the perfusion fluid significantly increased the concentrations of ortho- and meta-tyrosine or 2,3-DHBA in comparison to control animals. All increases determined were rapidly reversible after changing back to pre-stimulation conditions. The results demonstrate that aromatic hydroxylation of phenylalanine or salicylic acid is a useful technique to investigate hydroxyl free radical formation in vitro and in vivo. Advantages and disadvantages of both methods are discussed. (C) 2001 Elsevier Science B.V. All rights reserved.